From patchwork Mon Jan 17 16:26:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 12715582 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EF38EC433F5 for ; Mon, 17 Jan 2022 16:30:36 +0000 (UTC) Received: from localhost ([::1]:35966 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n9Utv-0004Ud-Ij for qemu-devel@archiver.kernel.org; Mon, 17 Jan 2022 11:30:35 -0500 Received: from eggs.gnu.org ([209.51.188.92]:32840) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n9Uqb-0000e1-IL for qemu-devel@nongnu.org; Mon, 17 Jan 2022 11:27:09 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:50355) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n9UqY-00012n-3j for qemu-devel@nongnu.org; Mon, 17 Jan 2022 11:27:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1642436825; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CkpUxkUoUtCQls59Hc1gVlJaxv9CHeIM+ut9u+oXBHA=; b=hRgyY4EnpzZSQaTKehdm9KD1mnWFvETH2MppIEtTur9CcPT6ItSQURfLtzMgkzVjYndQeS v+mIxgN3zN+QhXbcsoXdYK/ltblmxf6yG4vSizjKTr9s0LzbPemrtboOXp9hodc8AL5SC+ k/At9+lHeKz1+/hTfjc5KsiNCL+Zjq4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-401-nzBH2D7_MmG3_uZehg33qw-1; Mon, 17 Jan 2022 11:26:57 -0500 X-MC-Unique: nzBH2D7_MmG3_uZehg33qw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 60B22874981; Mon, 17 Jan 2022 16:26:56 +0000 (UTC) Received: from localhost (unknown [10.39.193.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CDCD25B94A; Mon, 17 Jan 2022 16:26:55 +0000 (UTC) From: Hanna Reitz To: qemu-block@nongnu.org Subject: [PATCH 2/2] iotests/block-status-cache: New test Date: Mon, 17 Jan 2022 17:26:49 +0100 Message-Id: <20220117162649.193501-3-hreitz@redhat.com> In-Reply-To: <20220117162649.193501-1-hreitz@redhat.com> References: <20220117162649.193501-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.129.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Nir Soffer , Hanna Reitz , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Add a new test to verify that want_zero=false block-status calls do not pollute the block-status cache for want_zero=true calls. We check want_zero=true calls and their results using `qemu-img map` (over NBD), and want_zero=false calls also using `qemu-img map` over NBD, but using the qemu:allocation-depth context. (This test case cannot be integrated into nbd-qemu-allocation, because that is a qcow2 test, and this is a raw test.) Signed-off-by: Hanna Reitz Reviewed-by: Nir Soffer --- tests/qemu-iotests/tests/block-status-cache | 130 ++++++++++++++++++ .../qemu-iotests/tests/block-status-cache.out | 5 + 2 files changed, 135 insertions(+) create mode 100755 tests/qemu-iotests/tests/block-status-cache create mode 100644 tests/qemu-iotests/tests/block-status-cache.out diff --git a/tests/qemu-iotests/tests/block-status-cache b/tests/qemu-iotests/tests/block-status-cache new file mode 100755 index 0000000000..1f2c3109d3 --- /dev/null +++ b/tests/qemu-iotests/tests/block-status-cache @@ -0,0 +1,130 @@ +#!/usr/bin/env python3 +# group: rw quick +# +# Test cases for the block-status cache. +# +# Copyright (C) 2022 Red Hat, Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . +# + +import os +import signal +import iotests +from iotests import qemu_img_create, qemu_img_pipe, qemu_nbd + + +image_size = 1 * 1024 * 1024 +test_img = os.path.join(iotests.test_dir, 'test.img') + +nbd_pidfile = os.path.join(iotests.test_dir, 'nbd.pid') +nbd_sock = os.path.join(iotests.sock_dir, 'nbd.sock') + + +class TestBscWithNbd(iotests.QMPTestCase): + def setUp(self) -> None: + """Just create an empty image with a read-only NBD server on it""" + assert qemu_img_create('-f', iotests.imgfmt, test_img, + str(image_size)) == 0 + + assert qemu_nbd('-k', nbd_sock, '-f', iotests.imgfmt, '-t', '-A', '-r', + f'--pid-file={nbd_pidfile}', test_img) == 0 + + def tearDown(self) -> None: + with open(nbd_pidfile, encoding='utf-8') as f: + pid = int(f.read()) + os.kill(pid, signal.SIGTERM) + os.remove(nbd_pidfile) + os.remove(test_img) + + def test_with_zero_bug(self) -> None: + """ + Verify that the block-status cache is not corrupted by a + want_zero=false call. + We can provoke a want_zero=false call with `qemu-img map` over NBD with + x-dirty-bitmap=qemu:allocation-depth, so we first run a normal `map` + (which results in want_zero=true), then using said + qemu:allocation-depth context, and finally another normal `map` to + verify that the cache has not been corrupted. + """ + + nbd_img_opts = f'driver=nbd,server.type=unix,server.path={nbd_sock}' + nbd_img_opts_alloc_depth = nbd_img_opts + \ + ',x-dirty-bitmap=qemu:allocation-depth' + + # Normal map, results in want_zero=true. + # This will probably detect an allocated data sector first (qemu likes + # to allocate the first sector to facilitate alignment probing), and + # then the rest to be zero. The BSC will thus contain (if anything) + # one range covering the first sector. + map_pre = qemu_img_pipe('map', '--output=json', '--image-opts', + nbd_img_opts) + + # qemu:allocation-depth maps for want_zero=false. + # want_zero=false should (with the file driver, which the server is + # using) report everything as data. While this is sufficient for + # want_zero=false, this is nothing that should end up in the + # block-status cache. + # Due to a bug, this information did end up in the cache, though, and + # this would lead to wrong information being returned on subsequent + # want_zero=true calls. + # + # We need to run this map twice: On the first call, we probably still + # have the first sector in the cache, and so this will be served from + # the cache; and only the subsequent range will be queried from the + # block driver. This subsequent range will then be entered into the + # cache. + # If we did a want_zero=true call at this point, we would thus get + # correct information: The first sector is not covered by the cache, so + # we would get fresh block-status information from the driver, which + # would return a data range, and this would then go into the cache, + # evicting the wrong range from the want_zero=false call before. + # + # Therefore, we need a second want_zero=false map to reproduce: + # Since the first sector is not in the cache, the query for its status + # will go to the driver, which will return a result that reports the + # whole image to be a single data area. This result will then go into + # the cache, and so the cache will then report the whole image to + # contain data. + # + # Note that once the cache reports the whole image to contain data, any + # subsequent map operation will be served from the cache, and so we can + # never loop too many times here. + for _ in range(2): + # (Ignore the result, this is just to contaminate the cache) + qemu_img_pipe('map', '--output=json', '--image-opts', + nbd_img_opts_alloc_depth) + + # Now let's see whether the cache reports everything as data, or + # whether we get correct information (i.e. the same as we got on our + # first attempt). + map_post = qemu_img_pipe('map', '--output=json', '--image-opts', + nbd_img_opts) + + if map_pre != map_post: + print('ERROR: Map information differs before and after querying ' + + 'qemu:allocation-depth') + print('Before:') + print(map_pre) + print('After:') + print(map_post) + + self.fail("Map information differs") + + +if __name__ == '__main__': + # The block-status cache only works on the protocol layer, so to test it, + # we can only use the raw format + iotests.main(supported_fmts=['raw'], + supported_protocols=['file']) diff --git a/tests/qemu-iotests/tests/block-status-cache.out b/tests/qemu-iotests/tests/block-status-cache.out new file mode 100644 index 0000000000..ae1213e6f8 --- /dev/null +++ b/tests/qemu-iotests/tests/block-status-cache.out @@ -0,0 +1,5 @@ +. +---------------------------------------------------------------------- +Ran 1 tests + +OK